U.S. patent application number 14/497999 was filed with the patent office on 2015-04-16 for structure of exhaust system for cda engine.
This patent application is currently assigned to Hyundai Motor Company. The applicant listed for this patent is Hyundai Motor Company. Invention is credited to Ho-Chan An, Seung-Hwan Lim, Chul-Min Park, Jong-Ho Seon.
Application Number | 20150101884 14/497999 |
Document ID | / |
Family ID | 52738152 |
Filed Date | 2015-04-16 |
United States Patent
Application |
20150101884 |
Kind Code |
A1 |
An; Ho-Chan ; et
al. |
April 16, 2015 |
STRUCTURE OF EXHAUST SYSTEM FOR CDA ENGINE
Abstract
A structure of an exhaust system for a CDA engine may include
three baffles coupled in a main muffler in a lateral direction, and
dividing an interior of the main muffler into a first space, a
second space, a third space, and a fourth space, a first connecting
pipe disposed outside the main muffler, connecting the second space
and the third space and having a passage in which exhaust gas
flows, a second connecting pipe disposed outside the main muffler,
connecting the second space and the third space, and having a
passage in which the exhaust gas flows, a first valve coupled to
the passage of the first connecting pipe, and a second valve
coupled to the passage of the second connecting pipe.
Inventors: |
An; Ho-Chan; (Hwasung-shi,
KR) ; Park; Chul-Min; (Seoul, KR) ; Lim;
Seung-Hwan; (Seoul, KR) ; Seon; Jong-Ho;
(Inchun-shi, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company |
Seoul |
|
KR |
|
|
Assignee: |
Hyundai Motor Company
Seoul
KR
|
Family ID: |
52738152 |
Appl. No.: |
14/497999 |
Filed: |
September 26, 2014 |
Current U.S.
Class: |
181/228 |
Current CPC
Class: |
F01N 13/02 20130101;
F01N 13/08 20130101; F01N 2240/36 20130101; F01N 13/087
20130101 |
Class at
Publication: |
181/228 |
International
Class: |
F01N 13/08 20060101
F01N013/08 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 2013 |
KR |
10-2013-122374 |
Claims
1. A structure of an exhaust system for a cylinder deactivation
(CDA) engine, which includes a first exhaust pipe which is
connected to a sub muffler connected to an exhaust pipe of a
vehicle, and through which exhaust gas passes, a main muffler which
is connected to the first exhaust pipe, and reduces noise generated
by the exhaust gas, and a second exhaust pipe which is connected to
the main muffler, and through which the exhaust gas passing through
the main muffler passes, the structure comprising: three baffles
coupled in the main muffler in a lateral direction, and dividing an
interior of the main muffler into a first space, a second space, a
third space and a fourth space; a first connecting pipe disposed
outside of the main muffler, the first connecting pipe connecting
the second space and the third space of the main muffler, and
having a passage in which the exhaust gas flows; a second
connecting pipe disposed outside the main muffler, the second
connecting pipe connecting the second space and the third space of
the main muffler, having a passage in which the exhaust gas flows,
and being formed to be relatively shorter than the first connecting
pipe; a first valve coupled to the passage of the first connecting
pipe and opening and closing the passage of the first connecting
pipe; and a second valve coupled to the passage of the second
connecting pipe and opening and closing the passage of the second
connecting pipe, wherein one of the three baffles, coupled between
the first space and the second space, and another of the three
baffles, which is coupled between the third space and the fourth
space, each have an aperture or a plurality of holes for the
exhaust gas to flow through.
2. The structure of claim 1, further comprising: a link unit
connecting the first valve and the second valve, wherein the first
valve and the second valve are coupled to the link unit while
having a phase difference of 90.degree., wherein the second valve
is closed when the first valve is opened, and wherein the second
valve is opened when the first valve is closed.
3. The structure of claim 1, wherein the three baffles include: a
first baffle disposed between the first space and the second space;
a second baffle disposed between the second space and the third
space; and a third baffle disposed between the third space and the
fourth space, wherein one end of the first connecting pipe extends
from the second space to the first space through the first baffle,
and is bent and protrudes to the outside of the main muffler, and
wherein another end of the first connecting pipe extends through
the third baffle from the third space to the fourth space, and is
bent and protrudes to the outside of the main muffler.
4. The structure of claim 3, wherein the first exhaust pipe extends
into the first space by passing through the third baffle, the
second baffle and the first baffle sequentially.
5. The structure of claim 3, wherein an end of the second exhaust
pipe extends into the fourth space by passing through the first
baffle, the second baffle and the third baffle sequentially.
6. The structure of claim 3, wherein a plurality of holes are
formed to the first baffle and the third baffle.
7. The structure of claim 1, wherein the first valve is an active
valve operated by a motor.
8. The structure of claim 2, wherein the first valve is an active
valve operated by a motor.
9. The structure of claim 2, wherein when the engine of the vehicle
is in a general mode, the second valve is opened, and the first
valve is closed, such that the exhaust gas in the main muffler
flows through the second connecting pipe.
10. The structure of claim 2, wherein when the engine of the
vehicle is in a CDA mode, the first valve is opened, and the second
valve is closed, such that the exhaust gas in the main muffler
flows through the first connecting pipe.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to Korean Patent
Application No. 10-2013-122374, filed Oct. 15, 2013, the entire
contents of which is incorporated herein for all purposes by this
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a structure of an exhaust
system for a vehicle, and more particularly, to a structure of an
exhaust system for a cylinder deactivation (CDA) engine, in which a
main muffler is divided into four spaces by three baffles, and a
first connecting pipe and a second connecting pipe which connect a
second space and a third space, a first valve which is coupled to a
passage of the first connecting pipe, and a second valve which is
coupled to a passage of the second connecting pipe are provided,
thereby reducing noise in the exhaust system with maximum
efficiency in accordance with characteristics of an engine.
[0004] 2. Description of Related Art
[0005] Recently, in respect to increased concerns about the
environment, major issues such as an environmental problem with
excessive emission of exhaust gas of a vehicle and consumers
preferring a high efficiency vehicle because of an increase in cost
of crude oil have become the focus.
[0006] Therefore, various technologies are being developed in order
to improve fuel efficiency of a vehicle, and increase output of an
engine.
[0007] For example, a variable induction system (VIS) which changes
a length or a cross-sectional area of an intake manifold in
accordance with air intake resistance that is varied depending on a
rotational region of an engine, a variable valve timing (VVT) which
adjusts an opening timing and an opening degree of a valve
depending on a rotational region of an engine, a variable valve
lift (VVL) which adjusts a lifting height of a valve, and a
cylinder deactivation (CDA) which switches some cylinders in an
engine to a non-operational state or a full operational state in
accordance with a traveling state in order to improve fuel
efficiency have been developed and used.
[0008] Among the aforementioned technologies, the CDA engine refers
to an engine that deactivates some of the cylinders when braking
the vehicle or when the vehicle travels at a constant speed, and
fuel supply and operations of intake/exhaust valves are stopped at
the deactivated cylinder side.
[0009] Because maximum output of the engine of the vehicle is
required only when the vehicle accelerates or travels up a slope,
fuel consumption may be reduced by not selectively igniting fuel in
the cylinder in a case in which the vehicle may be operated by
merely using partial output of the engine.
[0010] For example, in the case of the vehicle in which a
four-cylinder engine is mounted, because there is no reason to
operate all of the cylinders to generate power when braking the
vehicle in a traveling state, or when the vehicle is in a low idle
condition or a low load condition, two cylinders are deactivated,
and power is generated only by the remaining two cylinders.
[0011] However, the CDA engine has advantages in that fuel
consumption is low and fuel efficiency is high in comparison with a
typical engine, but has problems in that because fuel in some of
the cylinders is not ignited, the main component of engine noise is
changed and low frequency noise is increased.
[0012] In order to solve the aforementioned problems, in a
structure of an exhaust system for a CDA engine in the related art,
as illustrated in FIG. 1, an additional muffler 2 is mounted in an
exhaust pipe 4, which connects a sub muffler 1 and a main muffler
3, so that the entire exhaust pipe 4 is divided into several
segments, thereby reducing noise.
[0013] That is, in the CDA mode in which only two cylinders of the
four-cylinder engine are operated, a half order low frequency noise
component (a noise component that corresponds to C1, C3, and the
like among main components of engine noise), which is hardly
generated in a general mode, is additionally generated, and
combined with a low frequency resonance mode in the existing
exhaust pipe, and as a result, there is a problem in that noise
characteristics of the vehicle deteriorates.
[0014] Therefore, as illustrated in FIG. 2, the additional muffler
2 is mounted at peak points of a second resonance mode of the
exhaust system and a fourth resonance mode of the exhaust system so
as to reduce a resonance mode of the exhaust system.
[0015] However, in the case of the structure of the exhaust system
for a CDA engine in the related art in which a separate additional
muffler is mounted, there are still problems in that spaces for
other components (a fuel tank, a rear suspension, an interior
space, and the like) need to be decreased in order to mount the
additional muffler between the sub muffler and the main muffler,
and a weight of the vehicle is excessively increased because of the
additional muffler.
[0016] The information disclosed in this Background of the
Invention section is only for enhancement of understanding of the
general background of the invention and should not be taken as an
acknowledgement or any form of suggestion that this information
forms the prior art already known to a person skilled in the
art.
BRIEF SUMMARY
[0017] Various aspects of the present invention are directed to
providing a structure of an exhaust system for a CDA engine, in
which a main muffler is divided into four spaces, and connecting
pipes and valves, which connect the respective spaces, are
provided, thereby solving a problem with resonance in an exhaust
pipe due to an application of a CDA mode without mounting a
separate additional muffler.
[0018] According to various aspects of the present invention, a
structure of an exhaust system for a cylinder deactivation (CDA)
engine, having a first exhaust pipe which is connected to a sub
muffler connected to an exhaust pipe of a vehicle, and through
which exhaust gas passes, a main muffler which is connected to the
first exhaust pipe, and reduces noise generated by the exhaust gas,
and a second exhaust pipe which is connected to the main muffler,
and through which the exhaust gas passing through the main muffler
passes, may include three baffles coupled in the main muffler in a
lateral direction, and dividing an interior of the main muffler
into a first space, a second space, a third space, and a fourth
space, a first connecting pipe disposed outside of the main
muffler, the first connecting pipe connecting the second space and
the third space of the main muffler, and having a passage in which
the exhaust gas flows, a second connecting pipe disposed outside
the main muffler, the second connecting pipe connecting the second
space and the third space of the main muffler, having a passage in
which the exhaust gas flows, and being formed to be relatively
shorter than the first connecting pipe, a first valve coupled to
the passage of the first connecting pipe and opening and closing
the passage of the first connecting pipe; and a second valve
coupled to the passage of the second connecting pipe an opening and
closing the passage of the second connecting pipe, in which one of
the three baffles, coupled between the first space and the second
space, and another of the three baffles, coupled between the third
space and the fourth space, each have an aperture or a plurality of
holes for the exhaust gas to flow through.
[0019] The structure of the exhaust system for a CDA engine may
further include a link unit connecting the first valve and the
second valve, in which the first valve and the second valve are
coupled to the link unit while having a phase difference of
90.degree., the second valve is closed when the first valve is
opened, and the second valve is opened when the first valve is
closed.
[0020] The three baffles may include a first baffle disposed
between the first space and the second space, a second baffle
disposed between the second space and the third space, and a third
baffle disposed between the third space and the fourth space, in
which one end of the first connecting pipe may extend from the
second space to the first space through the first baffle, and may
be bent and protrude to the outside of the main muffler, and
another end of the first connecting pipe may extend through the
third baffle from the third space to the fourth space, and may be
bent and protrude to the outside of the main muffler.
[0021] The first exhaust pipe may extend into the first space by
passing through the third baffle, the second baffle and the first
baffle sequentially.
[0022] An end of the second exhaust pipe may extend into the fourth
space by passing through the first baffle, the second baffle and
the third baffle sequentially.
[0023] A plurality of holes is formed to the first baffle and the
third baffle.
[0024] The first valve may be an active valve that is operated by a
motor.
[0025] When the engine of the vehicle is in a general mode, the
second valve may be opened, and the first valve may be closed, such
that the exhaust gas in the main muffler flows only through the
second connecting pipe, and when the engine of the vehicle is in a
CDA mode, the first valve may be opened, and the second valve may
be closed, such that the exhaust gas in the main muffler flows only
through the first connecting pipe.
[0026] The present invention having the aforementioned
configuration includes the three baffles which are coupled in the
main muffler in a lateral direction, the first connecting pipe and
the second connecting pipe which connect the second space and the
third space, the first valve which is coupled to the passage of the
first connecting pipe, and the second valve which is coupled to the
passage of the second connecting pipe, thereby solving a problem
with resonance in an exhaust pipe due to an application of a CDA
mode while maintaining a structure of the existing exhaust
system.
[0027] That is, when the engine of the vehicle is in the CDA mode,
the first valve is opened, and the second valve is closed, such
that the exhaust gas in the main muffler flows only through the
first connecting pipe, and as a result, positions of the first
muffler and the second muffler are far away from each other,
thereby increasing a length of the entire exhaust system, and
achieving the effect that is obtained when another muffler is
further added.
[0028] When the engine of the vehicle is in a general mode, the
second valve is opened, and the first valve is closed, such that
the exhaust gas in the main muffler flows only through the second
connecting pipe, thereby reducing overall back pressure by
shortening a flow path of the exhaust gas.
[0029] The structure further includes a link unit which connects
the first valve and the second valve, in which the second valve is
closed when the first valve is opened, and the second valve is
opened when the first valve is closed, such that even when only one
valve is operated, the other valve may also be organically
operated.
[0030] By actively utilizing a structure of the existing exhaust
system, it is possible to minimize a decrease in space for the
other components (a fuel tank, a rear suspension, an interior
space, and the like) and an increase in weight of the vehicle,
which are caused by mounting an additional muffler.
[0031] It is understood that the term "vehicle" or "vehicular" or
other similar term as used herein is inclusive of motor vehicles in
general such as passenger automobiles including sports utility
vehicles (SUV), buses, trucks, various commercial vehicles,
watercraft including a variety of boats and ships, aircraft, and
the like, and includes hybrid vehicles, electric vehicles, plug-in
hybrid electric vehicles, hydrogen-powered vehicles and other
alternative fuel vehicles (e.g., fuels derived from resources other
than petroleum). As referred to herein, a hybrid vehicle is a
vehicle that has two or more sources of power, for example both
gasoline-powered and electric-powered vehicles.
[0032] The methods and apparatuses of the present invention have
other features and advantages which will be apparent from or are
set forth in more detail in the accompanying drawings, which are
incorporated herein, and the following Detailed Description, which
together serve to explain certain principles of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a top plan view illustrating an appearance in
which an additional muffler is mounted in a structure of an exhaust
system for a CDA engine in the related art.
[0034] FIG. 2 is an exemplified view schematically illustrating
resonance modes of the exhaust system and positions of the muffler
in the structure of the exhaust system for a CDA engine in the
related art.
[0035] FIG. 3 is a top plan view illustrating an appearance of an
exemplary structure of an exhaust system for a CDA engine according
to the present invention.
[0036] FIG. 4 is an enlarged view of part A of FIG. 3 according to
the present invention.
[0037] FIG. 5 is a perspective view illustrating an active valve
that is applied as a first valve in the exemplary structure of the
exhaust system for the CDA engine according to the present
invention.
[0038] FIG. 6 is an exemplified view illustrating a case in which
an engine of a vehicle is in a general mode in the exemplary
structure of the exhaust system for the CDA engine according to the
present invention.
[0039] FIGS. 7A and 7B are exemplified views schematically
illustrating resonance modes of the exhaust system and positions of
a muffler in the case in which the engine of the vehicle is in a
general mode in the exemplary structure of the exhaust system for
the CDA engine according to the present invention.
[0040] FIG. 8 is an exemplified view illustrating a case in which
the engine of the vehicle is in a CDA mode in the exemplary
structure of the exhaust system for the CDA engine according to the
present invention.
[0041] FIGS. 9A and 9B are exemplified views schematically
illustrating resonance modes of the exhaust system and positions of
the muffler in the case in which the engine of the vehicle is in
the CDA mode in the exemplary structure of the exhaust system for
the CDA engine according to the present invention.
[0042] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various features illustrative of the basic
principles of the invention. The specific design features of the
present invention as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment.
DETAILED DESCRIPTION
[0043] Reference will now be made in detail to various embodiments
of the present invention(s), examples of which are illustrated in
the accompanying drawings and described below. While the
invention(s) will be described in conjunction with exemplary
embodiments, it will be understood that the present description is
not intended to limit the invention(s) to those exemplary
embodiments. On the contrary, the invention(s) is/are intended to
cover not only the exemplary embodiments, but also various
alternatives, modifications, equivalents and other embodiments,
which may be included within the spirit and scope of the invention
as defined by the appended claims.
[0044] A structure of an exhaust system for a cylinder deactivation
(CDA) engine according to the present invention having a first
exhaust pipe 12 which is connected to a sub muffler 10 connected to
an exhaust pipe of a vehicle, and through which exhaust gas passes,
a main muffler 20 which is connected to the first exhaust pipe 12,
and reduces noise generated by the exhaust gas, and a second
exhaust pipe 14 which is connected to the main muffler 20, and
through which the exhaust gas passing through the main muffler 20
passes, may include a baffle 30 which includes three baffles 32, 34
and 36 which are coupled in the main muffler 20 in a lateral
direction, and divide the interior of the main muffler 20 into a
first space 22, a second space 24, a third space 26 and a fourth
space 28, a first connecting pipe 40 which is disposed outside the
main muffler 20, connects the first space 22 and the fourth space
28 of the main muffler 20, and has a passage in which the exhaust
gas flows, a second connecting pipe 50 which is disposed outside
the main muffler 20, connects the second space 24 and the third
space 26 of the main muffler 20, has a passage in which the exhaust
gas flows, and is formed to be relatively shorter than the first
connecting pipe 40, a first valve 42 which is coupled to the
passage of the first connecting pipe 40 so as to open and close the
passage of the first connecting pipe 40, and a second valve 52
which is coupled to the passage of the second connecting pipe 50 so
as to open and close the passage of the second connecting pipe 50,
in which the baffle 32, which is coupled between the first space 22
and the second space 24, and the baffle 36, which is coupled
between the third space 26 and the fourth space 28, have an
aperture or a plurality of holes so that the exhaust gas may flow
therethrough.
[0045] As illustrated in FIG. 3, the sub muffler 10 is connected to
an exhaust pipe (not illustrated) of the vehicle, and serves to
primarily reduce noise generated by the exhaust gas discharged from
the exhaust pipe.
[0046] The first exhaust pipe 12 is connected to a rear side of the
sub muffler 10 so as to supply the exhaust gas to the main muffler
20, and noise generated by the exhaust gas is secondarily reduced
by the main muffler 20 connected to the first exhaust pipe 12.
[0047] The second exhaust pipe 14 is connected to a rear side of
the main muffler 20, and the second exhaust pipe 14 serves to
discharge the exhaust gas discharged from the main muffler 20 to
the outside of the vehicle.
[0048] As illustrated in FIG. 6, the first exhaust pipe 12 is
extended from the sub muffler 10 to the first space 22 of the main
muffler 20, which will be described below, and allows the exhaust
gas passing through the sub muffler 10 to be supplied to the first
space 22 of the main muffler 20.
[0049] In addition, the second exhaust pipe 14 is extended from the
fourth space 28 of the main muffler 20, which will be described
below, to the outside of the vehicle, and allows the exhaust gas
passing through the interior of the main muffler 20 to be
discharged to the outside of the vehicle.
[0050] As illustrated in FIG. 3, the three baffles 32, 34 and 36
are coupled in the main muffler 20 in the lateral direction so as
to divide the interior of the main muffler 20 into the first space
22, the second space 24, the third space 26 and the fourth space
28, and in the illustrated exemplary embodiment, the space, which
is positioned at an uppermost end, is the first space 22, the
space, which is positioned immediately below the first space 22, is
the second space 24, the space, which is positioned immediately
below the second space 24, is the third space 26, and the space,
which is positioned at a lowermost end, is the fourth space 28.
[0051] In the illustrated exemplary embodiment, the baffle 30
includes a first baffle 32 that is disposed between the first space
22 and the second space 24, a second baffle 34 that is disposed
between the second space 24 and the third space 26, and a third
baffle 36 that is disposed between the third space 26 and the
fourth space 28.
[0052] The first baffle 32 and the third baffle 36 have an aperture
or a plurality holes so that the exhaust gas may freely flow
therethrough, and the second baffle 34 is formed in a blocked plate
shape, which has no aperture or hole, so that the exhaust gas flows
only through the first connecting pipe 40 or the second connecting
pipe 50 that will be described below.
[0053] In the illustrated embodiment, the first baffle 32 and the
third baffle 36 have the aperture or the plurality of holes so that
the exhaust gas flows therethrough, but the first baffle 32 and the
third baffle 36 may include other structures such as a plurality of
short pipes and a permeable membrane that may allow the exhaust gas
to flow therethrough.
[0054] As illustrated in FIG. 3, the first connecting pipe 40 and
the second connecting pipe 50 are coupled outside the main muffler
20, and specifically, the first connecting pipe 40 and the second
connecting pipe 50 connect the second space 24 and the third space
26 of the main muffler 20.
[0055] As illustrated in FIG. 6, the first connecting pipe 40 is
formed as a long pipe having an overall C-shape which has an inlet
and an outlet that are curved in directions toward the second space
24 and the third space 26, respectively, and the second connecting
pipe 50 is formed as a C-shaped pipe, and a length of the second
connecting pipe 50 is relatively shorter than that of the first
connecting pipe 40.
[0056] That is, one end of the first connecting pipe 40 is extended
from the second space 24 to the first space 22 through the first
baffle 32, and then bent and protrudes to the outside of the main
muffler 20, the other end of the first connecting pipe 40 is
extended from the third space 26 to the fourth space 28 through the
third baffle 36, and then bent and protrudes to the outside of the
main muffler 20, and the second connecting pipe 50 protrudes
directly from the second space 24 to the outside of the main
muffler 20, and is connected to the third space 26.
[0057] The first connecting pipe 40 and the second connecting pipe
50 may be formed in various shapes such as a `U` shape depending on
a shape of the main muffler 20, utilization of an overall space in
the exhaust system, and the type of vehicle.
[0058] As illustrated in FIGS. 3 and 4, the first valve 42 and the
second valve 52 are installed in the passages of the first
connecting pipe 40 and the second connecting pipe 50, respectively,
and shut off and permit the flow of the exhaust gas that flows
through the first connecting pipe 40 and the second connecting pipe
50.
[0059] As illustrated in FIG. 4, the first valve 42 and the second
valve 52 have general valve covers formed in a circular plate, and
open or close the first connecting pipe 40 and the second
connecting pipe 50 by being controlled by a control unit depending
on whether the CDA engine is operated.
[0060] The illustrated exemplary embodiment shows a case in which
the CDA mode is not operated (that is, operated in a general mode),
and shows a state in which the first valve 42 is laterally disposed
to close the first connecting pipe 40, and the second valve 52 is
longitudinally disposed to open the second connecting pipe 50 such
that the exhaust gas in the main muffler flows only through the
second connecting pipe.
[0061] As illustrated in FIG. 4, the first valve 42 and the second
valve 52 are connected by a link unit 60.
[0062] In the illustrated embodiment, the link unit 60 includes a
first link 62 which has one end coupled to the first valve 42, and
is moved depending on an opening and closing operation of the first
valve 42, a link arm 64 which has one end that is pivotally coupled
to the other end of the first link 62; and a second link 66 which
has one end that is pivotally coupled to the other end of the link
arm 64, and the other end that is coupled to the second valve
52.
[0063] As illustrated in FIG. 4, the first valve 42 and the second
valve 52 may be coupled to the link unit 60 while having a phase
difference by 90.degree., and the first link 62 and the second link
66 may be disposed in parallel with each other.
[0064] As illustrated in FIG. 6, when the first valve 42 is
laterally disposed, the first link 62 and the second link 66 are
generally inclined to the right, and the second valve 52 and the
first valve 42 are longitudinally disposed while having a phase
difference by 90.degree..
[0065] As illustrated in FIG. 8, when the first valve 42 is
longitudinally moved, the first link 62 is moved to the left, the
second link 66, which is connected to the link arm 64, is also
moved to the left along with the movement of the first link 62, and
the second valve 52 is moved by 90.degree. and laterally
disposed.
[0066] As illustrated in FIG. 5, the first valve 42 may be an
active valve that is operated by a motor 44, and the second valve
52 may be a manual valve that is operated along with the movement
of the first valve 42.
[0067] That is, when the first valve 42 is operated by the motor 44
and opens or closes the first connecting pipe 40, the second valve
52, which is connected with the first valve 42 through the link
unit 60, closes or opens the second connecting pipe 50 while
corresponding to the movement of the first valve 42.
[0068] An operational process and an operational effect of the
exemplary structure of the exhaust system for the CDA engine
according to the present invention will be described below.
[0069] As illustrated in FIG. 6, when the CDA mode is not operated,
that is, when the engine of the vehicle is in the general mode, the
exhaust gas is first supplied to the first space 22 in the main
muffler 20 through the first exhaust pipe 12.
[0070] Next, the exhaust gas supplied to the first space 22 flows
to the second space 24 through the aperture or the plurality of
holes formed in the first baffle 32, and flows to the third space
26 through the opened second connecting pipe 50.
[0071] The exhaust gas flowing to the third space 26 flows to the
fourth space 28 through the aperture or the plurality of holes of
the third baffle 36, and is discharged to the outside of the main
muffler 20 through the second exhaust pipe 14 connected to the
fourth space 28.
[0072] In addition, when the engine of the vehicle is in the
general mode, only a main order component (a noise component that
corresponds to C2, C4, and the like among main components of engine
noise) of engine noise is mainly generated, and as a result, the
possibility that the main order component is combined with low
frequency resonance mode of the exhaust pipe is relatively low.
[0073] Therefore, as illustrated in FIGS. 7A and 7B, when the
engine of the vehicle is in the general mode, a first muffler 21
including the first space 22 and the second space 24 of the main
muffler 20 is disposed to be adjacent to a second muffler 25
including the third space 26 and the fourth space 28 of the main
muffler 20, and serves to reduce back pressure throughout the
entire exhaust system.
[0074] That is, when the engine of the vehicle is in the general
mode, only the second connecting pipe 50, which is a relatively
short flow path, is opened, the first muffler 21 is disposed to be
adjacent to the second muffler 25, and as a result, an effect of
reducing back pressure throughout the exhaust system is
produced.
[0075] As illustrated in FIG. 8, likewise, even when the CDA mode
is operated, the exhaust gas is first supplied to the first space
22 in the main muffler 20 through the first exhaust pipe 12, and
flows to the second space 24 through the aperture or the plurality
of holes of the first baffle 32.
[0076] Next, the exhaust gas flowing to the second space 24 flows
to the third space 26 through the first connecting pipe 40, flows
to the fourth space 28 through the aperture or the plurality of
holes of the third baffle 36, and is discharged to the outside of
the main muffler 20 through the second exhaust pipe 14 connected to
the fourth space 28.
[0077] In addition, when the engine of the vehicle is in the CDA
mode, a half order component (a noise component that corresponds to
C1, C3, and the like among main components of the engine noise) of
the engine noise is additionally generated, and combined with the
low frequency resonance mode of the exhaust pipe, which causes
noise characteristics of a vehicle to deteriorate.
[0078] Therefore, as illustrated in FIGS. 9A and 9B, when the
engine of the vehicle is in the CDA mode, the main muffler 20 is
separated into the first muffler 21 and the second muffler 25 by
the first connecting pipe 40, and the first muffler 21 is disposed
to be adjacent to a peak point of a second resonance mode of the
exhaust system, thereby reducing resonance in the exhaust pipe.
[0079] As a distance between the first muffler 21 and the second
muffler 25 becomes longer, a length of the structure of the entire
exhaust system becomes longer, and the sub muffler 10 becomes
relatively closer to a peak point of a first resonance mode of the
exhaust system.
[0080] That is, when the engine of the vehicle is in the CDA mode,
only the first connecting pipe 40, which is a relatively long flow
path, is opened by the first valve, the second valve is closed,
such that the exhaust gas in the main muffler flows only through
the first connecting pipe, and the first muffler 21 and the second
muffler 25 are separated, thereby achieving the effect that is
obtained when another muffler is further added.
[0081] The foregoing descriptions of specific exemplary embodiments
of the present invention have been presented for purposes of
illustration and description. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and obviously many modifications and variations are
possible in light of the above teachings. The exemplary embodiments
were chosen and described in order to explain certain principles of
the invention and their practical application, to thereby enable
others skilled in the art to make and utilize various exemplary
embodiments of the present invention, as well as various
alternatives and modifications thereof. It is intended that the
scope of the invention be defined by the Claims appended hereto and
their equivalents.
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